Swansea have lost their last two Premier League games, at home to Hull and away to Leicester, after securing an opening-day win at Burnley.
And the visit of high-flying Chelsea on Sunday marks the start of a daunting run which also takes in Southampton, Manchester City, Liverpool and Arsenal before the middle of October.
"I think we have a good team," said Swansea manager Guidolin
"I am happy and now it is important to see the future with optimism.
"It is time to do well on the pitch because my disappointment is for the last game against Leicester because we prepared another game.
"We were prepared against a good side with a lot of energy, but for 30 minutes we suffered a lot and there is nothing more to say.
"We have to improve, we have to play more aggressively.
"We have to change this attitude because the Premier League is very hard, but with these players I am confident.
"And it's my responsibility when the team does not play well
I have to do better."
Guidolin even hinted at a change of formation from the 4-3-3 system he has employed this season.
Spanish striker Borja Baston could make the bench following the thigh injury which has prevented him playing any part since his record £15.5million move from Atletico Madrid.
But it is numbers in midfield that Guidolin might look to bolster to try and derail Chelsea opponents who have won their three opening Premier League matches.
"We are working on the pitch for different situations," said Guidolin.
"We have prepared a different shape as well and we have to be ready to play well and get a result.
"It is an important period when we hope to get more points and climb the table.
"But every year, every week, it's difficult to play against teams
Week after week we have to stay focused game by game."
Swansea fans could get a glimpse of new £5million centre-back Alfie Mawson, who joined the club just before the transfer deadline.
Mawson came through the same Barnsley set-up as England's Manchester City centre-back John Stones and Everton defender Mason Holgate, and Guidolin says the 22-year-old is ready for the rigours of the Premier League.
"It is too early to say if Alfie is a future leader, but he is a young player with good personality," said Guidolin.
"In training he is like other players, he is equal
He looks like he has been here a long time.
"Physically he is ready
He has good feet, is tall, and I like him.
"I think he will be a surprise for our fans, and I hope he has the same future as him (Stones)."
Source : PA
Source: PA